The present invention relates to a method for synchronization of performance data with defined time intervals in distributed computer environments.
In distributed computer environments, e.g. IBM S/390 Sysplex, performance data of the individual systems (single-system performance data) are scanned at specific intervals. The single-system performance data include in particular the CPU workload of a single system or the average response time of an I/O operation for a defined interval of a single system. Then, from the single-system performance data so-called network performance data are calculated, which are weighted as the mean value of the single-system performance data. If the network performance data exceed a defined value, the performance of every single system in the computer network must be analyzed. The analysis requires that a common interval be defined for the computer network and then that defined performance data of each single system be scanned and analyzed for that interval. The defined performance data may, for example, be the CPU workload in comparison to the average response time of I/O operations of each single system during the common interval. To make the said defined performance data of the single systems in a computer network at all comparable andxe2x80x94where appropriatexe2x80x94available for automated postprocessing, they should be scanned at the same rate, with the same time intervals. For technical reasons this can only be done with difficulty. The reasons lie in the fact that the available capacity of a system is not sufficient to scan the performance data in common mode with other systems, or that the options leading to restart of the data collector must be changed.
Based on experience, it can be assumed that the arrival of the performance data of the single systems, and the interval covered, is not uniform network-wide. The arrival time of the scanned performance data varies by milliseconds up to several minutes. The same applies to the duration of the individual intervals.
According to the current state of the art, all scanning intervals are processed in the order of their arrival. This results in tables with gaps, with rows of the same or similar time sequencing, which demands extensive manual editing by the user with a view to automated postprocessing.
It is therefore the object of the present invention to deliver a method which synchronizes the different scanning intervals of the scanned performance data of the single systems for a network-wide, clocked time interval with no significant data loss, thus making manual post-editing avoidable.
This and other objects are realized by postsynchronization of the scanned performance data. In this process, the performance data received from the single systems are sorted and edited by the following method:
1. According to their interval start time in ascending order.
2. According to their interval duration in descending order. As a result, the longest intervals can be processed first for a given interval.
3. The data sorted first form the basis for a common interval.
4. For the assignment of further data to a common interval, the mid-point time of the interval in question is taken. If it is within the common interval, the data are adopted into the common interval. If it is not, the new interval forms the basis for the next common interval.
5. Where several items of data from one system fall within one common interval, the last data record in each case is used.
The advantages of the present invention lie in the fact that the synchronized performance data are displayable in tabular form unambiguously and without gaps, and thus are available for postprocessing, for example as a bar chart. Manual evaluation is no longer necessary. The performance data can be subjected, with no manual editing, to a test and control program which evaluates the performance data and adapts the single systems to the specified performance data.